1. Technical Field
The present invention relates to a printing machine for printing on paper.
2. Related Art
Japanese Patent Application Publication No. 2006-256138 discloses a printing machine which has a circulating route including a reversing route configured to reverse paper and which performs double-side printing by transporting paper printed on one side thereof along the circulating route to reverse the sides of the paper and printing the paper on the other side thereof.
Moreover, a sealed letter formation system has been known in which an enclosing and sealing device is connected to a printing machine such as described above. In this sealed letter formation system, for each sealed letter to be formed, the printing machine performs printing on content paper and envelope paper, and the printed content paper and envelope paper are sent to the enclosing and sealing device. The enclosing and sealing device forms the printed envelope paper into an envelope, and seals the envelope having the printed content paper inserted therein, thus forming a sealed letter.
In the above-described sealed letter formation system, generally, the sizes of content paper and envelope paper are different from each other. Moreover, one-side printing or double-side printing can be set for each of content paper and envelope paper. Specifically, in the printing machine of this sealed letter formation system, control is performed to feed and transport content paper and envelope paper having different sizes, and further, performs four types of control of paper feed and transport according to combinations of one-side/double-side printing settings for content paper and envelope paper. Here, there are four combinations of one-side/double-side printing settings: both of content paper and envelope paper are subject to one-side printing; content paper is subject to one-side printing, and envelope paper is subject to double-side printing; content paper is subject to double-side printing, and envelope paper is subject to one-side printing; and both of content paper and envelope paper are subject to double-side printing.
In the printing machine of the above-described sealed letter formation system, paper feed and transport are controlled according to transport control patterns corresponding to the respective four combinations of one-side/double-side printing settings to perform high productivity printing.